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CKDRIVE.COM Version 2.0 Memory-Resident Driver for Add-On Computer Clocks IMPROVEMENTS IN THIS VERSION: Version 2.0 of CKDRIVE eliminates limitations of version 1.0 that required manual resetting for a new year or a leap year. The program now (1) advances the year automatically after midnight December 31 and (2) advances the date to February 29 instead of March 1 in leap years. Other changes improve synchronization between the add-on clock and the system clock; they now agree within about .01 sec. AUTHOR: Pete Petrakis COMPANY: Life Sciences Software 2020 Lake Heights Drive, R-301 Everett, Washington 98208 DISTRIBUTION: Distributed as shareware, which means "try before you buy," not "free." Payment of $5 is required if you find after 21 days that CKDRIVE meets your needs. Please send your payment (check or money order) to the above address, or call us at 206-337-7328 if you want to register with a MasterCard or VISA. DESCRIPTION: CKDRIVE is a memory-resident program that allows battery-powered add-on clocks to be set with the TIME and DATE commands in DOS. It also automatically updates the DOS clock/calendar an instant before the time and date are displayed whenever you use DOS's TIME or DATE command or are running a program that reads the time and date. CKDRIVE eliminates the need to run special clocksetting programs such as SETCLOCK (to set the add-on clock) and GETCLOCK (to refresh the DOS clock/calendar from the add-on clock). Whenever you want to change the time or date in your add- 1 on clock, just change the time or date in DOS, and CKDRIVE will automatically pass the change along to the add-on clock. Whenever you want to know the time or date in DOS, just ask for it in DOS, and CKDRIVE will refresh the DOS clock/calendar from the add-on clock an instant before the time or date is displayed on your screen. It's important to understand what is meant here by an add-on clock. Although the so-called slotless clocks, which plug into a ROM chip socket in your computer, are also add-on clocks, they are not the kind that CKDRIVE can work with. Nor will it work with the CMOS clock, which is a battery clock but not an add-on, and is an integral part of the original equipment in AT and better computers. The add-on clock that CKDRIVE is designed to work with is the type that comes on a circuit board that plugs into an expansion slot in your computer. Although some of these clocks, such as the one on the AST and Paradise multifunction cards, come from well known manufacturers, the clock-only type are typically quite inexpensive, with mail order prices ranging from $7.50 to $15, and very often neither the card nor the box it came in even has a manufacturer's name on it. For example, the box mine came in says only, "Add- On Card for '88 or '286 Personal Computer" and "Made in China." The word "clock" doesn't appear anywhere on the box and there is not a shred of documentation. The label on the diskette has only the handwritten letters, "CK," which presumably is an abbreviation for "CLOCK." That's the type of clock CKDRIVE is designed for, and what is meant here by "add-on clock." Despite its generic nature, this cheap real-time clock is quite accurate (as computer clocks go) and can track time to the millisecond (DOS can only display or set time to 1/100 second). Interestingly, the cheap no-name generic imports and the brand-name clock boards use the same type of clock chip and usually the same set of I/O ports. The base port is typically 240 hex, 2C0 hex, or 340 hex (occasionally 3C0 hex) and most of the boards allow you to select from a pair of these port addresses (usually 240 hex and 340 hex) by moving a jumper. When CKDRIVE is loaded, it checks to see which port addresses your add-on clock is using and configures itself accordingly 2 for memory-resident operation. If it finds no add-on clock at any of the four likely base ports, it reports that and quits. Some of the better known brands of add-on clocks, such as the one on the AST Six-Pack, come with their own memory-resident driver software. AST's driver is called ASTCLOCK, which goes memory- resident when you run it with /R on the command line. If your add-on clock came with that kind of software, you won't need CKDRIVE, although you could probably substitute CKDRIVE for the original driver software. If yours didn't come with that kind of software, then CKDRIVE is for you. RUNNING THE PROGRAM: Type CKDRIVE at the DOS prompt, preferably immediately after boot-up. The first thing CKDRIVE does when it's loaded is reset the DOS clock/calendar from the add-on clock. Thereafter, your DOS clock/calendar and your add-on clock will behave as a single clock, passing time and date to each other as needed. It's advisable to put CKDRIVE in your AUTOEXEC.BAT file so it can reset the DOS clock/calendar from the battery clock whenever you boot the system. Obviously it should go ahead of any program in the AUTOEXEC sequence that needs to check the DOS time and date. When loaded memory-resident, CKDRIVE takes less than 7k of RAM. AUTOMATIC YEAR ADVANCE AND LEAP YEAR ADJUSTMENT: Version 2.0 of CKDRIVE will automatically advance the year in both the add-on clock and the DOS clock/calendar the first time you request the date in January -- provided you requested the date at least once with CKDRIVE installed during the previous month. After midnight February 28 in a leap year it will automatically set the date to February 29 in both clocks -- provided you requested the date at least once with CKDRIVE installed between January 1 and February 28. (Requesting the date during those preliminary periods is practically unavoidable; you automatically request the date every time you save a file to disk, for example.) 3 SYNCHRONIZATION ACCURACY: When you set or read the time and date from DOS with CKDRIVE 2.0 loaded, the two clocks should agree within about .01 second, according to tests on my 8086 computer. However, agreement between the two clocks thereafter will depend on two factors: (1) the relative drift rates of the two clocks and (2) the frequency of setting or reading the time. Remember that all computer clocks drift, including DOS clock/calendars, battery- operated add-ons, and CMOS clocks. So, if the add-on clock drifts a few seconds a day, its deviation from the true time will be passed to the DOS clock/calendar whenever you ask for the time; the two clocks will then agree, but both will deviate from true time to the extent that the add- on clock does. KNOWN INCOMPATIBILITIES: If CKDRIVE is loaded, you should NEVER use the original software that came with your add-on clock for reading and setting it. If you do, the hours, minutes, seconds, fractions of seconds, month, and day of the month will probably be OK, but the year will probably be read or set wrong, from CKDRIVE's perspective. The reason is that the three ports available for year information in these clocks are for passive storage and are not controlled by the clock chip, allowing each software developer to devise his own method of storing and retrieving that information. Every program, including CKDRIVE, stores and reads information about years differently, so you should always read these clocks with the same software or software brand you used to set them. Besides, you won't need any of that software if you use 4 CKDRIVE; its purpose is to make those separate programs unnecessary. Use only one clock driver at a time. If you already have a driver that does what CKDRIVE does, there is no need to load CKDRIVE too. There will be trouble if you do; competition between the two drivers can slow things down dramatically. The Microsoft BASIC Professional Development System (version 7.0 of QuickBASIC) is incompatible with CKDRIVE. This is disappointing but not surprising since Microsoft recommends that no memory-resident programs at all be present when running that version of QuickBASIC. No system crash results when QuickBASIC 7 is loaded after CKDRIVE and the two clocks will continue to run, but each will be oblivious to the other thereafter. QuickBASIC 7 messes things up so the two clocks can no longer communicate with each other through CKDRIVE, and you'll have to reboot and reload CKDRIVE to get that interaction again. Finally, conflicts between memory-resident programs are a fact of life, and they may require you to modify the sequence in which such programs are loaded. PROGRAM HISTORY: CKDRIVE.COM was inspired by CLKDRV10.SYS, a driver for slot-type add-on clocks that is loaded as a device in the CONFIG.SYS file and was written by my friend Tom Strickland of Alexandria, Virginia. Tom's driver is part of my TIMESET 5.3 package (TSET53.EXE in Library 1 of Compuserve's IBMSYS forum, Library 2 in the MSOPSYS forum, or TIMSET53.ZIP, .ARC, etc. on bulletin boards around the country). Tom programs in assembly and C. I program in BASIC and wanted to see if I too could write a driver for these clocks using Microsoft's BASIC Professional Development System (BASIC 7.0) and linkable assembly routines from MicroHelp, Inc. and Crescent Software, as well as some special purpose assembly routines that I wrote. Crescent Software's P.D.Q. replacement library for QuickBASIC is mainly responsible for the program's small size (for a BASIC program) and its being a TSR. 5 How do the two drivers compare? Surprisingly well. With my 8086 computer, the DOS clock and the add-on clock usually agree within 0.01 sec, making version 2.0 of CKDRIVE.COM precise enough to be used with TIMESET. DISTRIBUTION AND DISCLAIMER: You can distribute CKDRIVE.COM to anyone you want provided you do not charge money for it (that's my department) and do not separate it from this document. Use of the program is at your own risk. Pete Petrakis does not claim that the program will work for everybody and he accepts no responsibility or liability for anything that might go wrong. PLEASE DON'T FORGET TO REGISTER Pete Petrakis Everett, Washington November 2, 1990 CIS 76555,1175 6